DE102015213634A1 - Solvent-based dry film and method of applying it to a substrate - Google Patents

Abstract

The present disclosure relates to a solvent-borne dry film and a method of applying a dry film to a substrate. The dry film includes a support and a resin layer. The resin layer contains a resin composition and a solvent, and the solvent is present in a total amount of at least 5% by weight based on the total weight of the resin layer. The dry film of the present invention can be applied to a substrate without the use of a prior art vacuum laminator. The application process is simple and more cost effective than the prior art methods.

Description

Field of the invention

The present invention relates to a solvent-containing dry film, in particular a dry film containing a polyimide layer. The present invention also relates to a method of applying a solvent-borne dry film to a substrate.

Description of the Prior Art

In recent years, it has been emphasized that electronic products should be lighter, thinner, shorter and smaller, and thus the size of various electronic parts and components must be much more reduced. Under such a development trend, there is more room for developing a flexible printed circuit (FPC) board, which is light and thin and has high temperature resistance and other properties, and can be mass-produced. The flexible circuit board can be found in various electronic products that are popular today, such as mobile phones, liquid crystal displays and organic light emitting diodes. The flexible circuit board is manufactured by arranging circuits and other electronic components on a flexible substrate, which has better flexibility compared to a circuit board using a conventional silicon substrate or glass substrate and thus can also be called a softboard.

Usually, a cover sheet is applied to a surface of the soft board as an insulating protective layer to protect copper circuits on the surface of the soft board and to improve the flexural strength of the circuit. A suitable material for the coversheet must have better heat resistance, dimensional stability, insulating performance and chemical resistance.

Generally, a method of laminating a coversheet to a softboard includes the steps of: first, processing the coversheet to a particular shape so that the coversheet has openings to expose the circuitry on the softboard; applying an adhesive layer to a surface of the cover sheet; and then aligning the coversheet with the corresponding positions on the softboard to perform lamination. However, the above method requires performing operations such as processing and forming apertures on a very thin coversheet, and lamination of the coversheet to the softboard relies substantially on a manual operation. Therefore, it leads to problems such as a low yield of the process and a high cost and thus does not meet the requirements for high precision assembly. In addition, there is a problem with the overflowing of the adhesive (bleeding out of adhesive).

In order to solve the above problems, it has been known that a photoimageable cover sheet (called photo-imageable coverlay, PIC) can be used for the improvement. The photopatternable coversheet does not require prior formation of openings, but if the photopatternable coversheet is laminated to a patterned circuit board, unwanted gas may remain between the patterned circuit board and the photopatternable coversheet, thus compromising the reliability and quality of the final products. To remove the gas between the circuit board and the photopatternable cover sheet, a vacuum laminator (eg, a vacuum laminator or a vacuum hot press) is generally used which first removes the air and then pressurizes it for lamination. However, in most cases, the process using the vacuum laminator can only achieve lamination in a single sheet fashion, i. H. it is necessary to pause for a while after each lamination to remove a test piece which has been laminated and to replace it with another test piece. The method using the vacuum laminator is not only time consuming and unable to meet the goal of rapid production, but also not cost effective due to the high cost of the device.

In addition, the photoimageable cover sheet conventionally used in the industry is mainly a dry film solder mask (called DSFM) which is predominantly composed of an epoxy resin or an acrylate resin. However, the coversheet made of the epoxy resin or the acrylate resin can not be applied to high-grade products because of insufficient heat resistance, insulating property, chemical resistance or mechanical strength.

Summary of the invention

In view of the foregoing, the present invention provides a novel solvent-containing dry film which has better heat resistance, insulating ability, chemical resistance and mechanical strength. The dry film of the present invention can be applied to a substrate without the use of a prior art vacuum laminator; the application process is simple and more cost effective than the prior art process.

The present invention further provides a method for applying a dry film to a substrate, which can effectively solve the problems of time consumption and the higher cost incurred when using a vacuum laminator for lamination.

The present invention provides a solvent-borne dry film comprising a support and a resin layer, wherein the resin layer comprises a resin and a solvent and the solvent is present in a total amount of at least 5% by weight based on the total weight of the resin layer.

The present invention also provides a method of applying a dry film to a substrate, comprising: laminating the dry film on the substrate in a manner that the resin layer of the dry film faces the substrate.

The dry film of the present invention can be applied to a substrate without the use of a prior art vacuum laminator. The application process is simple, can be performed with equipment available in the art, and is more cost effective than the prior art process; The dry film has better heat resistance, insulating ability, chemical resistance and mechanical strength, and can be applied to high-grade products.

Short description of

1 is a schematic diagram of a roll-to-roll process.

Detailed description of the invention

To facilitate the understanding of the disclosure herein, terms are hereby defined below.

The term "about" refers to an acceptable deviation from a particular value measured by one skilled in the art, depending in part on how the value is measured or determined.

In the present invention, the term "alkyl" refers to a saturated, straight or branched alkyl which preferably comprises from 1 to 30 carbon atoms and more preferably from 1 to 20 carbon atoms. Examples include, but are not limited to, methyl, ethyl, n -propyl, isopropyl, n -butyl, isobutyl, tert -butyl, amyl, hexyl and like groups.

In the present invention, the term "alkenyl" refers to an unsaturated, straight or branched alkyl containing at least one carbon-carbon double bond, which preferably comprises 2-30 carbon atoms and more preferably 10-20 carbon atoms. Examples include, but are not limited to, ethenyl, propenyl, methylpropenyl, isopropenyl, pentenyl, hexenyl, heptenyl, 1-propenyl, 2-butenyl, 2-methyl-2-butenyl, and similar groups.

In the present invention, the term "alkynyl" refers to an unsaturated, straight or branched alkyl containing at least one carbon-carbon triple bond which preferably comprises 2-30 carbon atoms and more preferably 10-20 carbon atoms. Examples include, but are not limited to, ethynyl, propargyl, 3-methyl-1-pentynyl, 2-heptynyl and like groups.

In the present invention, the term "aryl" or "aromatic compound" refers to an aromatic ring system comprising a monocyclic ring containing 6 carbon atoms, a bicyclic ring containing 10 carbon atoms, or a tricyclic ring containing 14 carbon atoms. Examples of the aryl include, but are not limited to, phenyl, tolyl, naphthyl, fluorenyl, anthryl, phenanthrenyl and like groups.

In the present invention, the term "halogenated alkyl" refers to a halo-substituted alkyl wherein the "halogen" denotes fluoro, chloro, bromo or iodo, preferably fluoro or chloro.

In the present invention, the term "alkoxy" refers to an alkyl bound to an oxygen atom. Examples include, but are not limited to, methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy, pentoxy, hexyloxy, benzyloxy, fluorenyloxy and like groups.

In the prior art, in order to prevent the dry film from generating a high concentration volatile organic compound during use of the dry film, and the phenomenon of excess glue (bleeding) caused by the flow of the applied glue (ie, the resin layer). during the storage of the dry film, a semi-finished product of the dry film which has been applied is sent into a furnace to dry the resin layer and completely adhere the resin layer to the support. The organic solvent is almost completely volatilized in this step. Therefore, the content of the organic solvent in conventional dry film products is generally less than 1% by weight.

In addition, a bubble phenomenon is usually observed when the dry film is applied to the lamination method of a flexible circuit board. The presence of bubbles leads to an abnormal quality of the dry film and thus affects the performance of the circuit board. As a result, a vacuum laminator is generally used to remove the air. However, as mentioned above, a vacuum laminator is not cost effective.

The present invention provides a solvent-borne dry film comprising a support and a resin layer, wherein the resin layer comprises a resin and a solvent. When the solvent is present in a total amount of at least 5% by weight based on the total weight of the resin layer, the dry film has a bubble-dissolving effect which can allow air to be mixed between a substrate and a dry film in the film Solvent containing dry film dissolves during lamination, thus solving the problem of bubbles generated by the dry film during the lamination process of the flexible printed circuit board.

The carrier used in the present invention may be any carrier known to those skilled in the art, such as glass or plastic. The plastic carrier is not subject to any particular restriction, and includes z. Polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); Polymethacrylate resins such as polymethylmethacrylate (PMMA); polyimide resins; Polystyrene resins; Polycycloolefinharze; polyolefin resins; Polycarbonate resins; Polyurethane resins; Triacetate cellulose (TAC); or a mixture thereof, but is not limited thereto. The preferred carriers are polyethylene terephthalate, polymethyl methacrylate, polycycloolefin resin or triacetate cellulose or a mixture thereof. More preferably, the carrier is polyethylene terephthalate. The thickness of the support is preferably in the range of about 16 μm to about 250 μm, which usually depends on the purpose of a desired optical product.

There is no particular limitation on the kind of the resin used in the resin layer, which is e.g. Example, an acrylate resin, an epoxy resin, a polyetherimide (PEI) resin or a polyimide resin may be. When applied to a high temperature process above 350 ° C, the resin is preferably a polyimide resin.

Through extensive investigations and repeated experiments, the inventors of the present invention have found that the solvent in the dry film of the present invention is contained in a total amount of at least 5% by weight, and preferably in a total amount of 15% by weight to 60% by weight. , based on the total weight of the resin layer, is present to more effectively solve the problem of bubbles generated by the dry film during lamination of the dry film to a flexible circuit board. The solvent is more preferably present in a total amount of from 15% to 50% by weight and most preferably in a total amount of from 15% to 47% by weight; In general, the lower limit may be 20% by weight. In one embodiment of the present invention, if the content of the solvent is too low (e.g., less than 15 wt% or even less than 5 wt%), the dry film tends to become rigid and brittle, and becomes is hardly laminated on a soft board, thus reducing the bubble-dissolving effect during the lamination process and easily causing a phenomenon of re-blistering (ie, the reoccurrence of bubbles after being dissolved). However, if the content of the solvent is too high, especially greater than 60 wt .-%, the surface of the Dry film is sticky and the performance is inferior and a better bubble-dissolving effect as expected during the lamination process can not be achieved.

According to a preferred embodiment of the present invention, the solvent used in the present invention comprises at least one solvent having a gas-dissolving action. The solvent having a gas-dissolving action can dissolve undesired gas located between the resin layer and the substrate, and therefore, the dry film has a gas-dissolving action, so that it can reduce the undesirable phenomenon due to the presence of the air between the resin layer and the substrate can solve the problem of bubbles generated during the lamination process of the dry film to the substrate without using a Vakuumlaminiergerät. The above-mentioned solvent having a gas dissolving effect is contained in an amount between 5% by weight to 60% by weight, preferably between 6% by weight to 45% by weight, more preferably between 7% by weight to 40% by weight %, based on the total weight of the resin layer.

The above-mentioned solvent having a gas-dissolving action is preferably selected from a first solvent, a second solvent and a combination thereof, wherein the first solvent and the second solvent are defined below.

The dry film of the present invention is applicable to printed circuit boards as a dry film solder mask or overcoat for protecting the coatings on printed circuit boards or is applicable to the surface of semiconductor packages. The layer formed by the dry film of the present invention is electrically insulated, can protect circuits, and can achieve excellent effects such as prevention of oxidation of the circuit and short-circuiting of solder.

In addition, the dry film of the present invention has a high resolution, a high developing speed, electrolytic plating resistance, electroless plating resistance, high temperature durability, high humidity durability and so on. Therefore, the dry film of the present invention can also be used as a photoresist in a printed circuit board or wafer related manufacturing process.

According to a preferred embodiment of the present invention, the solvent-containing dry film is a polyimide dry film comprising a support and a polyimide layer (a resin layer). The support is as defined above and is preferably polyethylene terephthalate. The polyimide layer may be a photosensitive or non-photosensitive polyimide layer. Preferably, the polyimide layer is a photosensitive polyimide layer. The polyimide layer comprises a polyimide resin and a solvent, wherein the polyimide resin may be a polyimide precursor or a soluble polyimide or a combination thereof, the types of which are defined below. The solvent is in a total amount of at least 5 wt .-%, preferably between 15 wt .-% to 60 wt .-%, more preferably between 15 wt .-% to 50 wt .-%, particularly preferably between 15 wt. % to 47 wt%, based on the total weight of the resin layer, present; In general, the lower limit may be 20% by weight. The solvent has a gas dissolving action and is selected from a first solvent, a second solvent, and a combination thereof, wherein the first solvent and the second solvent are defined below.

The flowability of the polyimide layer is influenced by its glass transition temperature. A higher glass transition temperature leads to poor flowability of the polyimide layer, and therefore it is difficult to perform lamination but easy to generate undissolved bubbles during the lamination process. With a lower glass transition temperature, the polyimide layer tends to become tacky during the lamination process, resulting in poor operability. The above-mentioned solvent also functions to adjust the glass transition temperature of the polyimide layer. According to an embodiment of the present invention, the polyimide layer in the present invention has a glass transition temperature preferably between -10 ° C and 20 ° C, and more preferably between 0 ° C and 15 ° C.

(a) polyimide precursor or soluble polyimide

polyimide precursor

There is no particular limitation on a polyimide precursor used in the present invention, which may be known to those skilled in the art, such as a polyamic acid, a polyamide ester, any material capable of producing polyimide by a reaction, or a mixture thereof. There are Various polyimide precursors have been developed in the art. For example, the in ROC (Taiwan) Patent Application No. 095138481 , No. 095141664 , No. 096128743 , No. 097151913 or no. 100149594 disclosed herein, the contents of which are hereby incorporated by reference in their entireties in this application.

wobei G eine vierwertige organische Gruppe ist;
P eine zweiwertige organische Gruppe ist;
R C₁-C₁₄-Alkyl, C₆-C₁₄-Aryl, C₆-C₁₄-Aralkyl, eine phenolische Gruppe oder eine ethylenisch ungesättigte Gruppe ist; und
n eine ganze Zahl von mehr 0, vorzugsweise eine ganze Zahl von 1 bis 1000 ist.The polyimide precursor has mainly a repeating unit of the formula (A):

wherein G is a tetravalent organic group;
P is a divalent organic group;
R is C ₁ -C ₁₄ alkyl, C ₆ -C ₁₄ aryl, C ₆ -C ₁₄ aralkyl, a phenolic group or an ethylenically unsaturated group; and
n is an integer greater than 0, preferably an integer from 1 to 1000.

Optionally, the polyimide precursor may be modified with different substituents / groups. For example, a photosensitive polyimide precursor may be prepared using photosensitive groups; the reactivity of a polyimide precursor or the properties of a polyimide prepared therefrom can be changed by adjusting the end groups attached to the repeating unit of the formula (A).

wobei G₁ unabhängig eine vierwertige organische Gruppe bedeutet;
jedes R_x unabhängig H oder eine ethylenisch ungesättigte Gruppe bedeutet;
jedes D unabhängig eine stickstoffhaltige heterocyclische Gruppe oder eine -OR* Gruppe bedeutet, wobei R* C₁-C₂₀-Alkyl ist;
jedes m eine ganze Zahl von 0 bis 100, vorzugsweise eine ganze Zahl von 5 bis 50, mehr bevorzugt eine ganze Zahl von 10 bis 25 ist; und
G, P und R wie vorstehend definiert sind. ROC (Taiwan) Patent Application No. 100149594 discloses polyimide precursors having one of the repeat units of formulas (1) to (4):

wherein G ₁ independently represents a tetravalent organic group;
each R _{x is} independently H or an ethylenically unsaturated group;
each D independently represents a nitrogen-containing heterocyclic group or an -OR * group, wherein R * is C ₁ -C ₂₀ alkyl;
each m is an integer of 0 to 100, preferably an integer of 5 to 50, more preferably an integer of 10 to 25; and
G, P and R are as defined above.

wobei R₁₂ Phenylen, C₁-C₈-Alkylen, C₂-C₈-Alkenylen, C₃-C₈-Cycloalkylen oder C₁-C₈-Hydroxylalkylen ist; und R₁₃ Wasserstoff oder C₁-C₄-Alkyl ist. Unter anderem ist die bevorzugte Gruppe der Formel (6) ausgewählt aus einer Gruppe bestehend aus

The ethylenically unsaturated group is not particularly limited, examples thereof include ethenyl, propenyl, methylpropenyl, n-butenyl, isobutenyl, ethenylphenyl, propenylphenyl, propenyloxymethyl, propenyloxyethyl, propenyloxypropyl, propenyloxybutyl, propenyloxypentyl, propenyloxyhexyl, methylpropenyloxymethyl, methylpropenyloxyethyl, methylpropenyloxypropyl, methylpropenyloxybutyl, methylpropenyloxypentyl, Methylpropenyloxyhexyl, a group represented by the following formula (5) and a group represented by the following formula (6), but are not limited thereto:

wherein R _{12 is} phenylene, C ₁ -C ₈ -alkylene, C ₂ -C ₈ -alkenylene, C ₃ -C ₈ -cycloalkylene or C ₁ -C ₈ -hydroxyalkylene; and R _{13 is} hydrogen or C ₁ -C ₄ alkyl. Among others, the preferred group of formula (6) is selected from a group consisting of

und einer Kombination davon, wobei X jeweils unabhängig Wasserstoff, Halogen, C₁-C₄-Perfluoralkyl oder C₁-C₄-Alkyl ist, und A und B jeweils unabhängig eine kovalente Bindung, C₁-C₄-Alkyl, C₁-C₄-Perfluoralkyl, Alkoxy, Silanyl, Sauerstoff, Schwefel, Carbonyl, Carboxylat, Sulfonyl, Phenyl, Biphenyl oder

sind, wobei J -O-, -SO₂-, -CH₂-, C(CF₃)₂ oder C(CH₃)₂ ist.The tetravalent organic groups G and G ₁ are not particularly limited, but examples include, but are not limited to, tetravalent aromatic groups or tetravalent aliphatic groups. The aromatic groups may be monocyclic or polycyclic rings and are preferably selected from a group consisting of

and a combination thereof, wherein each X is independently hydrogen, halo, C ₁ -C ₄ perfluoroalkyl or C ₁ -C ₄ alkyl, and A and B are each independently a covalent bond, C ₁ -C ₄ alkyl, C ₁ C ₄ perfluoroalkyl, alkoxy, silanyl, oxygen, sulfur, carbonyl, carboxylate, sulfonyl, phenyl, biphenyl or

where J is -O-, -SO ₂ -, -CH ₂ -, C (CF ₃ ) ₂ or C (CH ₃ ) ₂ .

wobei Z Wasserstoff oder Halogen ist.More preferably, the tetravalent organic groups G and G _{1 are} each independently an aromatic group selected from a group consisting of

where Z is hydrogen or halogen.

Most preferably, the tetravalent organic groups G and G _{1 are} each independently

The tetravalent aliphatic groups may be selected from a group consisting of

wobei,
R₁₇ jeweils unabhängig H, C₁-C₄-Alkyl, C₁-C₄-Perfluoralkyl, Methoxy, Ethoxy, Halogen, OH, COOH, NH₂ oder SH ist;
jedes a unabhängig eine ganze Zahl von 0 bis 4 ist;
jedes b unabhängig eine ganze Zahl von 0 bis 4 ist; und
R₁₈ eine kovalente Bindung oder eine Gruppe, ausgewählt aus

wobei,
c und d jeweils unabhängig eine ganze Zahl von 0 bis 20 sind;
R₁₇ und a wie vorstehend definiert sind; und
R₁₉ -S(O)₂-, -C(O)-, eine kovalente Bindung oder C₁-C₁₈-Alkyl ist.The divalent organic group P is not particularly limited such. B. but not limited to an aromatic group. Preferably, the divalent organic group P is each independently selected from a group consisting of

in which,
Each R ₁₇ is independently H, C ₁ -C ₄ alkyl, C ₁ -C ₄ perfluoroalkyl, methoxy, ethoxy, halo, OH, COOH, NH ₂ or SH;
each a is independently an integer from 0 to 4;
each b is independently an integer from 0 to 4; and
R _{18 is} a covalent bond or a group selected from

in which,
c and d are each independently an integer from 0 to 20;
R ₁₇ and a are as defined above; and
R _{19 is} -S (O) ₂ -, -C (O) -, a covalent bond or C ₁ -C ₁₈ alkyl.

wobei
jedes a unabhängig eine ganze Zahl von 0 bis 4 ist; und
jedes Z unabhängig Wasserstoff, Methyl, Trifluormethyl oder Halogen ist.More preferably, each divalent organic group P is independently selected from a group consisting of

in which
each a is independently an integer from 0 to 4; and
each Z is independently hydrogen, methyl, trifluoromethyl or halogen.

Most preferably, each divalent organic group P is independently

wobei jedes R₂₀ unabhängig H, Methyl oder Ethyl ist; und
e und f jeweils unabhängig eine ganze Zahl größer als 0 sind.The divalent organic group P may also be a non-aromatic group, e.g. B. but not limited to

wherein each R _{20 is} independently H, methyl or ethyl; and
e and f are each independently an integer greater than 0.

Preferably, the divalent organic group is P

wobei p eine ganze Zahl von 0 bis 10 ist, ist aber nicht darauf beschränkt. C₁-C₁₄-Alkyl kann z. B. Methyl, Ethyl, n-Propyl, Isopropyl, 1-Methylpropyl, 2-Methylpropyl, n-Butyl, Isobutyl, tert-Butyl, 1-Methylbutyl, 2-Methylbutyl, Pentyl, Hexyl, Heptyl oder Octyl sein, ist aber nicht darauf beschränkt. Die ethylenisch ungesättigte Gruppe ist wie vorstehend definiert. Das vorstehend erwähnte C₆-C₁₄-Aryl oder C₆-C₁₄-Aralkyl ist vorzugsweise ausgewählt aus einer Gruppe bestehend aus

In the polyimide precursors of formulas (1) to (4), each R is independently C ₁ -C ₁₄ alkyl, C ₆ -C ₁₄ aryl, C ₆ -C ₁₄ aralkyl, a phenolic group or an ethylenically unsaturated group. The C ₁ -C ₁₄ alkyl may, for. B. be one of the following groups:

where p is an integer from 0 to 10, but is not limited thereto. C ₁ -C ₁₄ alkyl may, for. Methyl, ethyl, n-propyl, isopropyl, 1-methylpropyl, 2-methylpropyl, n-butyl, isobutyl, tert-butyl, 1-methylbutyl, 2-methylbutyl, pentyl, hexyl, heptyl or octyl, but is not limited to this. The ethylenically unsaturated group is as defined above. The above-mentioned C ₆ -C ₁₄ -aryl or C ₆ -C ₁₄ -aralkyl is preferably selected from a group consisting of

R is most preferably selected from a group consisting of

In the polyimide precursors of formulas (1) and (3), each R _{x is} independently H or an ethylenically unsaturated group, the ethylenically unsaturated group being as defined above. According to the present invention, preferably each R _{x is} independently H, 2-hydroxypropyl methacrylate, ethyl methacrylate, Ethyl acrylate, propenyl, methylpropenyl, n-butenyl or isobutenyl; more preferably, each R _{x is} independently H or 2-hydroxypropyl methacrylate having the formula shown below:

In the polyimide precursors of formula (4), each D is independently a nitrogen-containing heterocyclic group or an OR * -containing group wherein R * is C ₁ -C ₂₀ alkyl. According to the present invention, the term "the nitrogen-containing heterocyclic group" refers to a non-aromatic 5- to 8-membered monocyclic ring having 1 to 3 heteroatoms, a 6- to 12-membered bicyclic ring having 1 to 6 heteroatoms, or an 11-bis 14-membered tricyclic ring having 1 to 9 heteroatoms (in which the heteroatoms are nitrogen); examples include, but are not limited to, pyridyl, imidazolyl, morpholinyl, piperidyl, piperazinyl, pyrrolidinyl, pyrrolidinonyl, and the like. Preferably, each D is independent:

Soluble polyimide

The soluble polyimide of the present invention is not particularly limited and may be any conventional soluble polyimide known to those skilled in the art, such as those disclosed in U.S. Pat ROC (Taiwan) Patent Application No. 097101740 , No. 099105794 No. 097138725 or No. 097138792, the contents of which are hereby incorporated by reference in their entirety into this application.

wobei C' eine vierwertige organische Gruppe ist;
E' eine zweiwertige organische Gruppe ist; und
t' eine ganze Zahl größer als 0, vorzugsweise eine ganze Zahl von 1 bis 1000 ist.The soluble polyimide of the present invention mainly has a repeating unit of the formula (B):

wherein C 'is a tetravalent organic group;
E 'is a divalent organic group; and
t 'is an integer greater than 0, preferably an integer from 1 to 1000.

The tetravalent organic group C 'has the same meaning as defined above for group G.

The divalent organic group E 'has the same meaning as defined above for group P.

Optionally, the soluble polyimide may be modified with different substituents / groups. For example, a photosensitive polyimide can be prepared using photosensitive groups. The properties of a soluble polyimide can be changed by adjusting the end groups attached to the repeating unit of the formula (B).

wobei R₂₀' eine gesättigte oder ungesättigte zweiwertige organische C₂-C₂₀-Gruppe, vorzugsweise

R₂₁' eine ungesättigte einwertige organische C₂-C₂₀-Gruppe ist, welche durch ein Heteroatom oder eine -OH-Gruppe substituiert sein kann; und C', E' und t' wie vorstehend definiert sind.A modified soluble polyimide obtained by tailoring the end groups attached to the repeating unit of the formula (B) includes, but is not limited to, the following

wherein R ₂₀ 'is a saturated or unsaturated divalent organic C ₂ -C ₂₀ group, preferably

R ₂₁ 'is an unsaturated monovalent organic C ₂ -C ₂₀ group which may be substituted by a heteroatom or an -OH group; and C ', E' and t 'are as defined above.

wobei A' und J' unabhängig eine vierwertige organische Gruppe sind; B' und D' unabhängig eine zweiwertige organische Gruppe sind; n' 0 oder eine ganze Zahl größer als 0 ist; m' eine ganze Zahl größer als 0 ist; und wenigstens eines von A' und B' eine oder mehrere lichtempfindliche Gruppe(n) G* aufweist, ausgewählt aus einer Gruppe bestehend aus

wobei R' eine ungesättigte Gruppe mit -C=C- ist oder ausgewählt ist aus einer Gruppe bestehend aus

und

und R₁₀' eine ungesättigte Gruppe mit einer Acrylatgruppe ist, wobei R₁' eine substituierte oder unsubstituierte, gesättigte oder ungesättigte organische C₁-C₂₀-Gruppe ist und R₂' eine ungesättigte Gruppe mit -C=C- ist.Preferably, the photosensitive group-modified soluble polyimide includes those having the following repeating units and in ROC (Taiwan) Patent Application No. 099105794 are disclosed, but are not limited to:

wherein A 'and J' are independently a tetravalent organic group; B 'and D' are independently a divalent organic group; n '0 or an integer greater than 0; m 'is an integer greater than 0; and at least one of A 'and B' has one or more photosensitive group (s) G * selected from a group consisting of

wherein R 'is an unsaturated group with -C = C- or is selected from a group consisting of

and

and R ₁₀ 'is an unsaturated group having an acrylate group, wherein R ₁ ' is a substituted or unsubstituted, saturated or unsaturated organic C ₁ -C ₂₀ group and R ₂ 'is an unsaturated group having -C = C-.

wobei R₄' und R₅' jeweils unabhängig H oder eine substituierte oder unsubstituierte organische C₁-C₇-Gruppe sind; und R₆' eine kovalente Bindung, -O- oder eine substituierte oder unsubstituierte organische C₁-C₂₀-Gruppe ist.The above-mentioned unsaturated group with -C = C- is preferably selected from a group consisting of

wherein R ₄ 'and R ₅ ' are each independently H or a substituted or unsubstituted C ₁ -C ₇ organic group; and R ₆ 'is a covalent bond, -O- or a substituted or unsubstituted C ₁ -C ₂₀ organic group.

wobei z eine ganze Zahl im Bereich von 0 bis 6 ist.More preferably, the above-mentioned unsaturated group with -C = C- is selected from a group consisting of

where z is an integer in the range of 0 to 6.

wobei z eine ganze Zahl im Bereich von 0 bis 6 ist.Most preferably, the above-mentioned unsaturated group is -C = C- selected from a group consisting of

where z is an integer in the range of 0 to 6.

ausgewählt sein kann,
wobei r' eine ganze Zahl größer als 0 und vorzugsweise eine ganze Zahl im Bereich von 1 bis 20 ist; 0', p' und q' jeweils unabhängig 0 oder eine ganze Zahl größer als 0, und vorzugsweise eine ganze Zahl im Bereich von 0 bis 10 sind; R₄', R₅' und R₆' die Bedeutungen wie vorstehend definiert haben; R₇' H oder eine substituierte oder unsubstituierte organische C₁-C₁₂-Gruppe ist; und R₈' eine kovalente Bindung ist oder ausgewählt ist aus einer Gruppe bestehend aus

R ₁ 'is a substituted or unsubstituted, saturated or unsaturated organic C ₁ -C ₂₀ group which is e.g. B. from a group consisting of

can be selected
wherein r 'is an integer greater than 0 and preferably an integer in the range of 1 to 20; 0 ', p' and q 'are each independently 0 or an integer greater than 0, and preferably an integer ranging from 0 to 10; R ₄ ', R ₅ ' and R ₆ 'have the meanings as defined above; R ₇ 'is H or a substituted or unsubstituted C ₁ -C ₁₂ organic group; and R ₈ 'is a covalent bond or is selected from a group consisting of

Preferably, R ₁ 'is selected from a group consisting of

wobei R₁₇' H oder Methyl ist, und K1 und K2 unabhängig eine ganze Zahl im Bereich von 0 bis 6 und vorzugsweise im Bereich von 2 bis 4 sind.R ₁₀ is an unsaturated group having an acrylate group. In the present invention, the unsaturated group having an acrylate group is preferable

wherein R ₁₇ 'is H or methyl, and K 1 and K 2 are independently an integer in the range of 0 to 6, and preferably in the range of 2 to 4.

According to the formula (4 '), the compound of the formula (4') has two polymerization units when n 'is not zero. These two polymerization units can be randomly arranged. That is, the polymerization units in formula (4 ') may have other arrangements besides a regular arrangement of m' consecutive units having a photosensitive group followed by n 'consecutive units having a non-photosensitive group.

(b) solvent

The solvent having a gas dissolving effect used in the present invention may be a first solvent, a second solvent or a combination thereof.

The first solvent may also provide other effects in addition to the gas-dissolving effect. For example, the first solvent may be used as a solvent required during a process of resin synthesis or formulation (e.g., a solvent required to synthesize a polyimide precursor or a solvent required for a soluble polyimide). , The first solvent is preferably a polar aprotic solvent and may, for. B. from dimethyl sulfoxide (DMSO), diethyl sulfoxide, N, N-dimethyl-methanamide (DMF), N, N-diethyl-methanamide, N, N-dimethylacetamide (DMAc), N, N-diethylacetamide, N-methyl-2 pyrrolidone (NMP), N-ethyl-2-pyrrolidone (NEP), phenol, o-cresol, m-cresol, p-cresol, xylenol, halogenated phenol, catechol, tetrahydrofuran (THF), dioxane, dioxolane, propylene glycol monomethyl ether (PGME) , Tetraethylene glycol dimethyl ether (TGDE), methanol, ethanol, butanol, 2-butoxyethanol, γ-butyrolactone (GBL), xylene, toluene, hexamethylphosphoramide, propylene glycol monomethyl ether acetate (PGMEA) and a mixture thereof.

perfluoraromatischen Verbindungen, C₂-C₂₀-Perfluoralkanen, Tri-(C₁-C₆-perfluoralkyl)aminen, Perfluorethern, C₆-C₁₆-Alkanen und einer Kombination davon,
wobei R₁'', R₉'' und R₁₀'' unabhängig H, C₁-C₂₀-Alkyl, C₂-C₂₀-Alkenyl oder C₂-C₂₀-Alkinyl sind;
R₇'' H oder C₁-C₃-Alkyl ist;
R₂'' C₁-C₁₀-Alkyl oder C₁₀-C₃₀-Alkenyl ist;
R₃'' C₂-C₂₀-Alkyl, -C₁-C₁₀-Alkyl-O-C₁-C₁₀-alkyl oder C₁₀-C₃₀-Alkenyl ist;
R₄'' und R₅'' unabhängig C₁-C₁₀-Alkyl sind oder R₄'' und R₅'' zusammen mit den Sauerstoffatomen, an die sie gebunden sind, einen 5-6-gliedrigen Heterocyclus bilden;
R₆'' C₁-C₁₅-Alkyl oder C₄-C₈-Cycloalkyl ist;
R₈'' C₂-C₁₀-Alkylen ist; und
R₁₁'' und R₁₂'' unabhängig C₁-C₁₀-Alkyl sind.In addition to the gas-dissolving action, the second solvent may also be useful for adjusting the solvent polarity. Compared to the first solvent, the second solvent is a bubble-dissolving solvent having a better gas-dissolving action. The second solvent is preferably selected from

perfluoroaromatic compounds, C ₂ -C ₂₀ perfluoroalkanes, tri (C ₁ -C ₆ perfluoroalkyl) amines, perfluoroethers, C ₆ -C ₁₆ alkanes and a combination thereof,
wherein R ₁ ", R ₉ " and R ₁₀ "are independently H, C ₁ -C ₂₀ alkyl, C ₂ -C ₂₀ alkenyl or C ₂ -C ₂₀ alkynyl;
R ₇ '' is H or C ₁ -C ₃ alkyl;
R ₂ "is C ₁ -C ₁₀ alkyl or C ₁₀ -C ₃₀ alkenyl;
R ₃ '' is C ₂ -C ₂₀ alkyl, C ₁ -C ₁₀ alkyl, OC ₁ -C ₁₀ alkyl or C ₁₀ -C ₃₀ alkenyl;
R ₄ "and R ₅ " are independently C ₁ -C ₁₀ alkyl or R ₄ "and R ₅ " together with the oxygen atoms to which they are attached form a 5-6 membered heterocycle;
R ₆ "is C ₁ -C ₁₅ alkyl or C ₄ -C ₈ cycloalkyl;
R ₈ "is C ₂ -C ₁₀ alkylene; and
R ₁₁ "and R ₁₂ " are independently C ₁ -C ₁₀ alkyl.

Through extensive studies and repeated experiments, the inventors of the present invention have found that the solvents containing fluorine, an alkyl group or an ester group have better gas-dissolving activity and are the preferred second solvents. The types of the second solvent are exemplified below.

The first solvent is present in an amount of from 0.5% to 50%, preferably from 1% to 28%, more preferably from 1.5% to 25% by weight. -%, based on the total weight of the resin layer, present. If the second solvent exists, the second solvent is in an amount of 3 Wt .-% to 45 wt .-%, preferably between 5 wt .-% to 43 wt .-%, more preferably between 7 wt .-% to 40 wt .-%, based on the total weight of the resin layer, present.

According to an embodiment of the present invention, the solvent-containing dry film comprises a support and a resin layer; when the carrier is polyethylene terephthalate and the resin layer is a polyimide layer, the total amount of the solvent of the present invention is between 15 wt% and 60 wt%, preferably between 20 wt% and 50 wt%, and more preferably between 25% by weight and 47% by weight, based on the total weight of the resin layer. The solvent used in the present invention comprises a first solvent and an optional second solvent; the first solvent has a gas dissolving effect and is a solvent used for the synthesis of a polyimide precursor or a soluble polyimide, and the types of the first solvent are as defined above. The amount of the first solvent is between 0.5 wt% and 50 wt%, preferably between 1 wt% and 28 wt%, and more preferably between 1.5 wt% and 25 wt%. %, based on the total weight of the resin layer. In addition, when the second solvent having a better gas dissolving effect is added, a better gas dissolving effect can be obtained, so that unwanted gas between a substrate and the polyimide layer is rapidly dissolved into the polyimide layer and no bubble re-blistering phenomenon occurs over a long period of time dissolving occurs without the use of a vacuum laminator. The types of the second solvent are as defined above. If present, the amount of second solvent is between 3 weight percent and 45 weight percent, preferably between 5 weight percent and 43 weight percent, and more preferably between 7 weight percent and 40 weight percent. %, based on the total weight of the resin layer. If the amount of the second solvent is too low (eg, lower than 3% by weight), the dry film has a poorer bubble-dissolving effect during the lamination process, so that it can not achieve a significant and rapid bubble-dissolving effect and easily a phenomenon a re-bubbling may occur. However, if the amount of the second solvent is too high (eg, higher than 45% by weight), the dry film is excessively hydrophobic, so that a glue flow occurs; the compatibility of the polyimide layer with another component is poor, so that the polyimide layer has a poor adhesion to the substrate and the performance is inferior. In addition, environmental awareness has grown in recent years, and the industry is focusing on processes that can be performed at a lower temperature to reduce energy consumption. In the case where low-temperature processing is employed, the second solvent may be present in an amount between 7% by weight and 15% by weight, and the dry film of the present invention still achieves a good bubble-dissolving effect.

eine Kombination davon sein können.The second solvent is preferably a bubble-dissolving solvent containing fluorine, an alkyl group or an ester group. Bubble-dissolving solvents containing an ester group have a better gas-dissolving effect, which z. B:

a combination of them.

Method for forming a dry film

• (1) Herstellen einer Polyimidharzzusammensetzung, welche ein Polyimidharz und ein erstes Lösemittel umfasst;
• (2) gegebenenfalls Zugeben eines zweiten Lösemittels oder eines Additivs zu der Polyimidharzzusammensetzung;
• (3) Aufbringen der in Schritt (2) hergestellten Polyimidharzzusammensetzung auf einen Träger, um ein Trockenfilm-Halbfertigprodukt zu bilden, welches den Träger und eine Harzschicht umfasst;
• (4) Einbringen des Trockenfilm-Halbfertigprodukts in einen Ofen, um es zu erwärmen und zu trocknen, um einen Teil des Lösemittels zu entfernen, wodurch die Gesamtmenge des Lösemittels in der Harzschicht verringert wird; Gewährleisten der Existenz einer passenden Menge des Lösemittels (z. B. wenigstens 5 Gew.-%, bezogen auf das Gesamtgewicht der Harzschicht) in dem Trockenfilm-Halbfertigprodukt durch Steuern der Erwärmungsdauer und Temperatur, und Bilden eines lösemittelhaltigen Trockenfilms, wobei das Lösemittel in einer Gesamtmenge von wenigstens 5 Gew.-%, bezogen auf das Gesamtgewicht der Harzschicht, vorhanden ist; und
• (5) gegebenfalls Aufbringen eines Schutzfilms auf die Harzschicht.

For example, the dry film of the present invention can be prepared according to the following steps (a polyimide resin is taken as an example):

• (1) preparing a polyimide resin composition comprising a polyimide resin and a first solvent;
• (2) optionally adding a second solvent or an additive to the polyimide resin composition;
• (3) applying the polyimide resin composition prepared in step (2) to a support to form a dry film semi-finished product comprising the support and a resin layer;
• (4) placing the dry film semi-finished product in an oven to heat and dry it to remove a portion of the solvent, thereby reducing the total amount of solvent in the resin layer; Ensuring the existence of an appropriate amount of the solvent (e.g., at least 5% by weight based on the total weight of the resin layer) in the dry film semi-finished product by controlling the heating time and temperature, and forming a solvent-containing dry film, wherein the solvent is in one Total amount of at least 5% by weight, based on the total weight of the resin layer, is present; and
• (5) optionally applying a protective film to the resin layer.

In the polyimide resin composition indicated in the above step (1), the amount of the first solvent is not particularly limited and can be adjusted by a skilled person if necessary. Based on the total weight of the composition, the added amount of the first solvent is 20% by weight to 90% by weight, preferably 45% by weight to 80% by weight. The types of the first solvent are as defined above.

The types of the second solvent in the above step (2) are as defined above.

In the above step (2), any suitable additive known to those skilled in the art may optionally be added to the resin composition. If z. For example, when the resin layer is a photosensitive polyimide layer, the additive comprises a photoinitiator and an acrylate monomer. Kinds of the above-mentioned photosensitive polyimide resin are defined as above in this application.

The photoinitiator is used to generate a free radical upon irradiation with light and to initiate polymerization due to the transfer of the free radical. There is no particular limitation on the photoinitiator useful in the composition of the photosensitive polyimide resin of the present invention. Preferably, the photoinitiator comprises a compound capable of generating a free radical by absorbing the light having a wavelength of about 350 nm to about 500 nm.

The amount of the photoinitiator is about 0.01 part by weight to about 20 parts by weight, and preferably about 0.05 part by weight to about 5 parts by weight, based on 100 parts by weight of the photosensitive polyimide. The suitable for use in the present invention photoinitiator may, for. B. selected from a group consisting of benzophenone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis-4,4'-diethylaminobenzophenone, benzophenone, camphorquinone, 3,5-bis (diethylaminobenzylidene) -N-methyl-4-piperidone , 3,5-bis (dimethylaminobenzylidene) -N-methyl-4-piperidone, 3,5-bis (diethylaminobenzylidene) -N-ethyl-4-piperidone, 3,3'-carbonylbis (7-diethylamino) coumarin, 3,3'-carbonylbis (7-dimethylamino) coumarin, riboflavin tetrabutyrate, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2,4-dimethylthioxanthone, 2,4- Diethylthioxanthone, 2,4-diisopropylthioxanthone, 3,5-dimethylthioxanthone, 3,5-diisopropylthioxanthone, 1-phenyl-2- (ethoxycarbonyl) oxyiminopropan-1-one, benzoin ethers, benzoin isopropyl ethers, benzanthrone, 5-nitroacenaphthene, 2-nitrofluorene, anthrone , 1,2-benzanthraquinone, 1-phenyl-5-mercapto-1H-tetrazole, thioxanthen-9-one, 10-thioxanthenone, 3-acetylindole, 2,6-di (p-dimethylaminobenzal) -4-cadboxycyclohexanone, 2, 6-Di (p-dimethylaminobenzal) -4-hydroxycyclohexanone, 2,6-di (p-diet hylaminobenzal) -4-carboxycyclohexanone, 2,6-di (p-diethylaminobenzal)) - 4-hydroxycyclohexanone, 4,6-dimethyl-7-ethylaminocoumarin, 7-diethylamino-4-methylcoumarin, 7-diethylamino-3- (1 methylbenzoimidazolyl) coumarin, 3- (2-benzoimidazolyl) -7-diethylaminocoumarin, 3- (2-benzothiazolyl) -7-diethylaminocoumarin, 2- (p-dimethylaminostyryl) benzooxazole, 2- (p-dimethylaminostyryl) quinoline, 4- (p -Dimethylaminostyryl) quinoline, 2- (p-dimethylaminostyryl) benzothiazole, 2- (p-dimethylaminostyryl) -3,3-dimethyl-3H-indole and a combination thereof. The preferred photoinitiator is benzophenone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide or a combination thereof.

The above-mentioned acrylate monomer is an acrylate monomer containing at least one -C = C- bond, preferably a multifunctional acrylate monomer containing two or more -C = C- bonds. The addition of such a monomer can form cross-linking between molecules and improve the practicality of the composition. Preferably, an acrylate monomer selected from the following groups can be used in the present invention: Ethylene glycol dimethacrylate, ethylene glycol diacrylate, bisphenol A-ethylene glycol modified diacrylate, bisphenol A-ethylene glycol modified dimethacrylate, bisphenol F-ethylene glycol modified diacrylate, bisphenol F-ethylene glycol modified dimethacrylate, propylene glycol dimethacrylate, tripropylene glycol diacrylate, ethoxylated trimethylolpropane triacrylate, dipentaerythritol hexaacrylate , Trimethylolpropane triacrylate, trimethylolpropane trimethyl acrylate, pentaerythritol triacrylate, pentaerythritol trimethyl acrylate and a combination thereof. When an acrylate monomer is present, based on 100 parts by weight of a photosensitive polyimide precursor, the added amount of the acrylate monomer is about 5 to 80 parts by weight, preferably 10 to 40 parts by weight.

Types of the carrier in the above step (3) are as defined above.

There is no particular limitation on the heating temperature and time in the above step (4). The heat treatment in step (4) is mainly aimed at reducing the amount of the solvent in the resin layer. For example, the heating may be carried out to dry at an appropriate temperature between 80 ° C and 250 ° C for 30 seconds to 10 minutes. During a conventional dry film-making process, to prevent the dry film from generating a high-concentration volatile organic compound during use of the dry film, and the phenomenon of excess glue (bleeding) caused by the flow of the applied glue during storage of the dry film, the heating is often performed so that the solvent is almost completely removed (up to an amount of less than 1% by weight) in a solvent removal step corresponding to the above step (4) , However, unlike the conventional step, in the present invention, the solvent is not completely removed in the solvent removal step, but remains in a proper amount (e.g., at least 5% by weight based on the total weight of the resin layer), which can give room for a gas-dissolving effect, thus achieving a favorable blister-dissolving effect.

The solvent in the above step (4) is selected from a first solvent, a second solvent and a mixture thereof. In general, due to the difference in the boiling points of various solvents, the total amount of the solvent in the dry film can be controlled by properly adjusting the heating temperature and time. As described above, the total amount of the solvent in the dry film obtained in step (4) is preferably between 15% by weight and 60% by weight based on the total weight of the polyimide resin layer, and the amount of the second solvent is preferably between 3% by weight % and 45% by weight, based on the total weight of the polyimide resin layer, to obtain the effect that unwanted gas between a substrate and the polyimide layer is quickly dissolved into the polyimide layer without a vacuum laminating apparatus and no dissolution for a long time after the dissolution Phenomenon of re-bubbling occurs.

The protective film in step (5) closes z. Polyester resin, polyethylene terephthalate (PET) or polyethylene naphthalate (PEN); Polymethacrylate resin such as polymethyl methacrylate (PMMA); polyimide resin; Polystyrene resin; polycycloolefin; polyolefin resin; Polycarbonate resin; Polyurethane resin; Triacetate cellulose (TAC) or a combination thereof, but is not limited thereto. Preferably, the protective film is polyethylene terephthalate, polymethyl methacrylate, polycycloolefin resin, triacetate cellulose or a combination thereof. More preferably, the protective film is polyethylene terephthalate.

In the prior art, the dry film is applied as a coversheet or passivation layer to a printed circuit board or wafer. Due to high investment costs for the vacuum laminator, a long process cycle and a low production speed, a bottleneck is formed in conventional production. The solvent-containing dry film of the present invention can utilize, without the vacuum laminating apparatus, properties of the solvent having a gas-dissolving action to easily dissolve undesired gas. Therefore, the dry film of the present invention can be applied to a field such as a printed circuit board, a wafer, a display, or a touch panel using a simpler and more cost-effective method than that used in the prior art.

Method for applying a dry film to a substrate

• (a) nach dem Entfernen eines optionalen Schutzfilms, das Laminieren des Trockenfilms auf das Substrat auf eine Weise, dass eine Harzschicht des Trockenfilms dem Substrat zugewandt ist; und
• (b) gegebenenfalls das Durchführen eines blasenauflösenden Arbeitsgangs unter Druck.

The present invention further provides a method of applying a dry film to a substrate, comprising:

• (a) after removing an optional protective film, laminating the dry film on the substrate in such a manner that a resin layer of the dry film faces the substrate; and
• (b) optionally, performing a bubble-dissolving operation under pressure.

The above substrate, as already defined, may include a flexible circuit board, a wafer, a display or a touch panel, or the like.

The above lamination method includes roll lamination, hot press, vacuum lamination, or vacuum press.

Preferably, the above step (a) may be carried out in a roll-to-roll manner. A roll-to-roll process known to those skilled in the art refers to the steps of withdrawing a sample from a rolled up material, processing the sample, and winding the processed sample on a roll. For example, as in 1 shown, a substrate A pulled out from a roll of the substrate A, with a dry film of a dry film roll 1 using the rollers 2 and 3 laminated and then wound up to form a product B. Therefore, the dry film of the present invention can be laminated on the substrate by a continuous process, which is convenient for simplifying the process and speeding up the process.

In order to achieve that unwanted gas between the substrate and the resin layer can be quickly dissolved into the resin layer without a vacuum laminating apparatus, the above step (b) can be carried out by using a bubble-dissolving pressure-reducing step known to a person skilled in the art. For example, the support to which the dry film has been applied is preferably wound on a roll, and then the whole roll is transferred to an autoclave to dissolve the bubbles. The pressurization is preferably carried out at a temperature between 30 ° C and 100 ° C and at a pressure between 2 atm and 10 atm for 10 to 60 minutes.

Since the dry film of the present invention contains a solvent having a gas dissolving effect, undesirable gas remaining between the substrate and the polyimide layer can be dissolved in the polyimide layer during lamination of the polyimide layer on the substrate. Therefore, it effectively improves the quality of the end products. In addition, the air dissolved in the polyimide layer may be removed in subsequent processing steps, such as exposure, baking, and development, or may optionally be removed using additional processing steps, such as heating. For example, a desired structure may be formed on a dry film by steps such as exposure, baking (e.g., at 80 ° C to 100 ° C for 5 minutes to 20 minutes), and development after lamination of the dry film onto a circuit board ; Subsequently, a polyimide precursor is cyclized by heating and polymerized to a polyimide. In such steps (particularly the baking and / or heating step), the air dissolved in the polyimide layer can be removed along with volatilization of the solvent.

Use of the dry film of the present invention

The dry film of the present invention may be laminated to a substrate such as a printed circuit board, a wafer, a display, or a touch panel using general lamination techniques without a vacuum laminator. Therefore, in comparison with the prior art, the lamination of the dry film of the present invention can be performed by simpler steps using an apparatus which is more readily available. Overall, the present invention is more cost effective than the prior art employing a vacuum laminator or other processing device.

In addition, without the use of a vacuum laminator, the dry film of the present invention can effectively reduce the amount of gas present between the resin layer and the substrate, thereby improving the quality of the products.

Examples

Synthesis Example 1: Photosensitive polyimide precursor resin PI-1

21.81 g (0.1 mol) of pyromellitic dianhydride (hereinafter referred to as "PMDA") was dissolved in 200 g of N-methyl-2-pyrrolidone (hereinafter referred to as "NMP"). The resulting mixture was then heated to 50 ° C and stirred for 2 hours to react. 1.161 g (0.01 mol) of 2-hydroxyethyl acrylate (hereinafter referred to as "HEA") was added slowly and then the mixture was stirred for reaction for 2 hours at a solid temperature of 50 ° C. Then, 20.024 g (0.1 mol) of 4,4'-oxydianiline (hereinafter referred to as "ODA") was added to the solution, and after complete dissolution, it was further stirred for reaction for 6 hours at a solid temperature of 50 ° C. a photosensitive Polyimide precursor resin PI-1 in which the solids content is about 17 wt .-%. The solids content is the weight percentage of nonvolatile materials in PI-1 and may be e.g. Baking the resin at 250 ° C or 300 ° C for 1 hour, measuring the difference in weight of the resin before and after baking to obtain the actual weight of the nonvolatile materials, and calculating the weight percentage of the nonvolatile material in PI first

Synthetic Example 2: Photosensitive polyimide precursor resin PI-2

21.81 g (0.1 mol) PMDA was dissolved in 200 g NMP. The resulting mixture was then heated to 50 ° C and stirred for 2 hours to react. 13.01 g (0.01 mol) of 2-hydroxyethyl methacrylate (hereinafter referred to as "HEMA") was added slowly and then the reaction mixture was stirred for 2 hours at a solid temperature of 50 ° C. Then, 20.024 g (0.1 mol) of ODA was added to the solution, and after complete dissolution, it was further stirred for reaction for 6 hours at a solid temperature of 50 ° C to form a photosensitive polyimide precursor resin PI-2, in which Solids content about 21 wt .-% is.

Synthesis Example 3: Photosensitive polyimide precursor resin PI-3

21.81 g (0.1 mol) PMDA was dissolved in 200 g NMP. The resulting mixture was then heated to 50 ° C and stirred for 2 hours to react. 0.601 g (0.01 mol) of isopropanol was added slowly, followed by stirring for 2 hours at a solid temperature of 50 ° C. Then, 32.02 g (0.1 mol) of 2,2'-bis (trifluoromethyl) benzidine (hereinafter referred to as "TFMB") was added to the solution and after complete dissolution it was allowed to react for 6 hours at a solid temperature of 50 ° C to form a photosensitive polyimide resin precursor PI-3, in which the solids content is about 21 wt .-%.

Synthesis Example 4: Carboxyl group-containing soluble polyimide PI-4

43.62 g (0.2 mol) of PMDA and 30.43 g (0.2 mol) of 3,5-diaminobenzoic acid (hereinafter referred to as "DABA") were provided and mixed with 300 ml of NMP. The resulting mixture was stirred for 1 hour at room temperature. Then, the mixture was warmed to 50 ° C and stirred for 4 hours. After 4 hours, 50 ml of toluene were added. Water was removed by a Dean-Stark apparatus at 150 ° C. Toluene was removed after completion of the removal of the water, and a solution of a carboxyl group-containing polyimide PI-4 in which the solid content is about 19% by weight was obtained.

Synthesis Example 5: Soluble polyimide PI-5 having an isocyanate-modified carboxyl group

370 g of PI-4 was provided, and 1.4 g of 1-methylimidazole (hereinafter referred to as "1-MI"), 15.5 g of 2-isocyanatoethyl methacrylate (hereinafter referred to as "IEM") and 0.1 g of phenothiazine (hereinafter as "PTZ"). The mixture was stirred for 1 hour at room temperature. After 1 hour, the mixture was heated to 60 ° C and stirred for 6 hours to obtain a soluble polyimide PI-5 having an isocyanate-modified carboxyl group in which the solid content is about 19% by weight.

Synthesis Example 6: Hydroxyl group-containing soluble polyimide PI-6

88.85 g (0.2 mol) of 4,4 '- (hexafluoroisopropylidene) diphthalic anhydride (hereinafter referred to as "6FDA") and 57.26 g (0.2 mol) of 2,2-bis (3-amino-4 -hydroxyphenyl) propane (hereinafter referred to as "BAPA") were prepared and mixed with 300 ml of NMP The resulting mixture was stirred at room temperature for 1 hour, then the mixture was warmed to 50 ° C and stirred for 4 hours Water was removed by a Dean-Stark apparatus at 150 ° C. After completion of the removal of the water and removal of the toluene, a solution of a hydroxyl group-containing polyimide PI-6 was obtained in which the solids content was about 32 Wt .-% is.

Synthetic Example 7: Soluble polyimide PI-7 having an isocyanate-modified hydroxyl group

440 g PI-6 was provided and mixed with 1.67 g 1-MI, 36.86 g IEM and 0.12 g PTZ. The mixture was stirred for 1 hour at room temperature. After 1 hour, the mixture was heated to 60 ° C and stirred for 6 hours to obtain a soluble polyimide PI-7 having an isocyanate-modified hydroxyl group in which the solid content is about 37% by weight.

Synthesis Example 8: Soluble polyimide PI-8 with a diisocyanate-modified carboxyl group

370 g PI-4 was provided and mixed with 1.4 g 1-MI, 13.01 g HEMA, 14.01 g tetramethylene diisocyanate (hereinafter referred to as "TMDC") and 0.1 g PTZ. The mixture was stirred for 1 hour at room temperature. After 1 hour, the mixture was heated to 60 ° C and stirred for 6 hours to obtain a soluble polyimide PI-8 having a diisocyanate-modified carboxyl group in which the solid content is about 24% by weight.

Synthetic Example 9: Polyimide PI-9 having a diisocyanate-modified hydroxyl group

440 g PI-6 was provided and mixed with 1.67 g 1-MI, 13.01 g HEMA, 14.01 g TMDC and 0.12 g PTZ. The mixture was stirred for 1 hour at room temperature. After 1 hour, the mixture was heated to 60 ° C and stirred for 6 hours to obtain a polyimide PI-9 having a diisocyanate-modified hydroxyl group in which the solid content is about 36% by weight.

The abbreviations used in the following examples are defined below.

Synthesis Example 10: Isocyanate-modified soluble polyimide PI-10

64.85 g (0.2 mol) of DA1 and 42.46 g (0.2 mol) of 2,2'-dimethylbiphenyl-4,4'-diamine (hereinafter referred to as "DMDB") were provided and mixed with 300 ml of NMP mixed. The mixture was stirred for 1 hour at room temperature. Then, the mixture was warmed to 50 ° C and stirred for 4 hours. After 4 hours, 50 ml of toluene was added. Water was removed by a Dean-Stark apparatus at 130 ° C. After completion of the removal of the water and removal of the toluene, the solution was cooled to room temperature. 7 g (0.05 mol) of 2-isocyanatoethyl acrylate (hereinafter referred to as "2-IEA"), 0.05 g of 1-MI and 0.06 g of PTZ were added. The solution was heated to 80 ° C and stirred for 8 hours to obtain an isocyanate-modified soluble polyimide PI-10 in which the solid content is about 27% by weight.

Synthesis Example 11: Isocyanate-modified polyimide PI-11

73.256 g (0.2 mol) DA2 and 42.46 g (0.2 mol) DMDB were provided and mixed with 350 ml NMP. The mixture was stirred for 1 hour at room temperature. Then, the mixture was warmed to 50 ° C and stirred for 4 hours. After 4 hours, 50 ml of toluene was added. Water was removed by a Dean-Stark apparatus at 130 ° C. After completion of the removal of the water and removal of the toluene, the solution was cooled to room temperature. 7 g (0.05 mol) of 2-IEA, 0.05 g of 1-MI and 0.06 g of PTZ were added. The solution was heated to 80 ° C and stirred for 8 hours to obtain an isocyanate-modified polyimide PI-11 in which the solid content is about 26% by weight.

Synthetic Example 12: Isocyanate-modified polyimide PI-12

100.074 g (0.2 mol) DA3 and 42.46 g (0.2 mol) DMDB were provided and mixed with 450 ml NMP. The mixture was stirred for 1 hour at room temperature. Then, the mixture was warmed to 50 ° C and stirred for 4 hours. After 4 hours, 50 ml of toluene was added. Water was removed by a Dean-Stark apparatus at 130 ° C. After completion of the removal of the water and removal of the toluene, the solution was cooled to room temperature. 7 g (0.05 mol) of 2-IEA, 0.05 g of 1-MI and 0.06 g of PTZ were added. The solution was heated to 80 ° C and stirred for 8 hours to obtain an isocyanate-modified polyimide PI-12 in which the solid content is about 24% by weight.

Synthetic Example 13: Hydroxyl group-containing soluble polyimide PI-13

88.85 g (0.2 mol) of 6FDA, 28.63 g (0.1 mol) of BAPA and 23.03 g (0.1 mol) of bis (4-aminophenoxy) methane (hereinafter referred to as "MEMG") prepared and mixed with 300 ml of NMP. The mixture was stirred for 1 hour at room temperature. Then, the mixture was warmed to 50 ° C and stirred for 4 hours. After 4 hours, 50 ml of xylene was added. Water was removed by a Dean-Stark apparatus at 150 ° C. Upon completion of removal of the water and removal of xylene, a hydroxy group-containing polyimide PI-13 is obtained in which the solids content is about 31% by weight.

Synthesis Example 14: Epoxy-modified soluble photosensitive polyimide PI-14

140.5 g of polyimide PI-13 obtained from Example 13 was provided and admixed with 6.11 g (0.05 mol) of glycidyl methacrylate (hereinafter referred to as "GMA"), 0.015 g of tetrabutylammonium bromide (hereinafter referred to as "TBAB") and 0.06 g of hydroquinone monomethyl ether (hereinafter referred to as "MEHQ"). The mixture was then heated to 90 ° C and stirred for 12 hours to obtain a soluble photosensitive polyimide PI-14 in which the solid content is about 31% by weight.

Synthesis Example 15: -COOH group-containing soluble polyimide PI-15

100.074 g (0.2 mol) DA3 and 42.46 g (0.2 mol) DMDB were provided and mixed with 450 ml NMP. The mixture was stirred for 1 hour at room temperature. Then, the mixture was warmed to 50 ° C and stirred for 4 hours. After 4 hours, 50 ml of toluene was added. Water was removed by a Dean-Stark apparatus at 130 ° C. After completion of the removal of the water and removal of the toluene, a COOH group-containing polyimide PI-15 was obtained in which the solid content is about 24% by weight.

Synthesis Example 16: Epoxy-modified soluble photosensitive polyimide PI-16

142.5 g PI-15, obtained from Example 15, was provided and added with 6.11 g (0.05 mol) GMA, 0.015 g TBAB and 0.06 g MEHQ. The mixture was then heated to 90 ° C and stirred for 12 hours to obtain an epoxy-modified soluble photosensitive polyimide PI-16 in which the solid content is about 25% by weight.

Synthesis Example 17: Photosensitive polyimide precursor resin PI-17

2.181 g (0.01 mol) of PMDA was dissolved in 200 g of NMP and the solution was warmed to 50 ° C and stirred for 2 hours. 1.161 g (0.01 mol) of HEA was added slowly and then stirred for reaction for 2 hours at a solid temperature of 50 ° C. Then, 18.018 g (0.09 mol) of ODA was added to the solution, and after complete dissolution, 18.0216 g (0.09 mol) of PMDA was added. The mixture was further stirred for reaction for 6 hours at a solid temperature of 50 ° C. 2.0024 g (0.01 mol) of ODA was added. The mixture was stirred for 1 hour to obtain a photosensitive polyimide precursor resin PI-17 in which the solid content is about 17% by weight.

Synthesis Example 18: Solution of an amine group-containing polyimide PI-18

32.023 g (0.1 mol) TFMB and 39.98 g (0.09 mol) 6FDA were provided and mixed with 300 ml NMP. The mixture was stirred for 1 hour at room temperature. Then, the mixture was warmed to 50 ° C and stirred for 4 hours. After 4 hours, 50 ml of toluene was added. Water was removed by a Dean-Stark apparatus at 150 ° C. After the completion of the removal of the water and removal of the toluene, a solution of an amine group-containing polyimide PI-18 was obtained in which the solids content is about 19% by weight.

Synthetic Example 19: Polyimide solution PI-19

32.023 g (0.1 mol) of TFMB and 0.9806 g (0.02 mol) of maleic anhydride were provided and mixed with 300 ml of NMP. The mixture was stirred for 1 hour at room temperature. 39.98 g (0.09 mol) of 6FDA was added and the mixture was then warmed to 50 ° C and stirred for 4 hours. After 4 hours, 50 ml of toluene was added. Water was heated by a Dean-Stark apparatus at 150 ° C. After completion of the removal of the water and removal of the toluene, a polyimide solution PI-19 was obtained in which the solids content is about 19% by weight.

Synthetic Example 20: Polyimide solution PI-20

32.023 g (0.1 mol) of TFMB and 4.9664 g (0.02 mol) of 4-phenylethynylphthalic anhydride were provided and mixed with 300 ml of NMP. The mixture was stirred for 1 hour at room temperature. 39.98 g (0.09 mol) of 6FDA was added and the mixture was then warmed to 50 ° C and stirred for 4 hours. After 4 hours, 50 ml of toluene was added. Water was removed by a Dean-Stark apparatus at 150 ° C. After completion of the removal of the water and removal of the toluene, a polyimide solution PI-20 was obtained in which the solid content is about 20% by weight.

Synthetic Example 21: Polyimide solution PI-21

32.023 g (0.1 mol) of TFMB and 48.8664 g (0.11 mol) of 6FDA were provided and mixed with 300 ml of NMP. The mixture was stirred for 1 hour at room temperature and then warmed to 50 ° C and stirred for 4 hours. After 4 hours, 50 ml of toluene was added. Water was removed by a Dean-Stark apparatus at 150 ° C. After completion of the removal of the water and removal of the toluene, a polyimide solution PI-21 was obtained in which the solid content is about 20% by weight.

Synthetic Example 22: Solution of a photosensitive acrylic group-containing polyimide PI-22

32.023 g (0.1 mol) of TFMB and 48.8664 g (0.11 mol) of 6FDA were provided and mixed with 300 ml of NMP. The mixture was stirred for 1 hour at room temperature and then warmed to 50 ° C and stirred for 4 hours. After 4 hours, 50 ml of toluene was added. Water was removed by a Dean-Stark apparatus at 150 ° C. After completion of the removal of the water and removal of the toluene, 2.322 g (0.02 mol) of HEA was added at 50 ° C, and the mixture was stirred for 4 hours to obtain a solution of a photosensitive acrylic group-containing polyimide PI-22 which is about 21% by weight solids.

Synthetic Example 23: Polyimide solution PI-23

32.023 g (0.1 mol) of TFMB and 48.8664 g (0.11 mol) of 6FDA were provided and mixed with 300 ml of NMP. The mixture was stirred for 1 hour at room temperature and then warmed to 50 ° C and stirred for 4 hours. After 4 hours, 50 ml of toluene was added. Water was removed by a Dean-Stark apparatus at 150 ° C. After completion of the removal of the water and removal of the toluene, 0.02 mol of 3- (phenylethynyl) aniline was added at 50 ° C and the mixture was stirred for 4 hours to obtain a polyimide solution PI-23 in which the solids content was about 23 Wt .-% is.

Production of a dry film

A second solvent listed in Tables 1 to 6 was optionally added to 100 parts by weight of a polyimide precursor solution or a solution of a soluble polyimide prepared in Synthesis Examples 1-23. The added amount of the second solvent was as shown in each table. Subsequently, each composition was uniformly coated on a polyethylene terephthalate (PET) substrate using a blade coater and baked in an oven. The baking temperature and time are shown in each table. Thus, a dry film comprising a coating with the polyimide precursor or a coating with the soluble polyimide was obtained; the thickness of the coating was about 20 μm. Before coating, the amount of first solvent and the amount of second solvent added (parts by weight) to 100 parts by weight of the polyimide precursor solution or the solution of the soluble polyimide. While after drying, the amount of the first solvent and the amount of the second solvent (wt%) were based on the total weight of the resin layer.

Dry film test

The above dry film was tested for solvent content and physical properties including surface tack, glass transition temperature (Tg), lamination etc. tests. Each of the tests is described below:

Test of the solvent content

0.01 g of polyimide precursor coating or soluble polyimide coating (the PET support is not included) was taken and dissolved in dimethyl sulfoxide (DMSO). A 7890GC gas chromatograph, manufactured by Agilent Technologies Co., Ltd., with the Model: DB1701 column (0.53 mm, 30 mm, 1.5 μm) was used to perform quantitative gas chromatography.

Surface tack test

A 20 x 20 cm dry film was taken and gently placed on a 30 x 30 cm copper foil with the polyimide layer of the dry film facing the copper foil so that the polyimide layer of the dry film was completely covered with the copper foil. After 30 seconds, the dry film was peeled off the copper foil to observe the percentage of dry film remaining on the surface of the copper foil. No remainder was designated as 0, if all was left, it was designated 10, 0-10% remainder was designated 1, and so on.

Measurement of Tg

The Tg of the dry films was measured using a thermomechanical analyzer (TMA, a TA Q400 instrument manufactured by Texas Instruments Incorporated). The measuring range was between -50 ° C and 100 ° C and the temperature was raised at 10 ° C / min.

Lamination test

A 20 x 20 cm dry film was taken and laminated to a copper-clad laminate with a circuit formed thereon using hot rolls at a temperature of 80 ° C at 3 kgf / cm ² pressure with the polyimide layer of the dry film facing the copper-clad laminate , The copper-clad laminate has a line width of L / S = 30/30 μm. After standing for 4 hours, the conditions of bubbles were then observed and classified into 10 classes according to the remaining portion of bubbles in which 0 indicates that the residual rate of bubbles is 0%, 10 indicates that the residual rate of bubbles is 100% % is, 1 indicates that the residual rate of bubbles is 0-10%, etc.

Pressure treatment test

A 20 x 20 cm dry film was taken and laminated to a copper-clad laminate with a circuit formed thereon using hot rolls at a temperature of 80 ° C at 3 kgf / cm ² pressure with the polyimide layer of the dry film facing the copper-clad laminate. The copper-clad laminate has a line width of L / S = 30/30 μm. Then, it was placed in an autoclave under the pressure treatment condition of 50 ° C / 5 atm / 30 min. The conditions of bubbles were observed after the application of the pressure and classified into 10 classes according to the residual rate of the bubbles, in which 0 indicates that the residual rate of bubbles is 0%, 10 indicates that the residual rate of bubbles is 100%, 1 indicated in that the residual rate of bubbles is 0-10%, etc.

Blistering test

After performing the blister-removing operation under pressure, the film (20 x 20 cm) was placed in environmental conditions of 25 ° C and 50-70% RH for 24 hours. After 24 hours, the conditions of bubbles were observed using an optical microscope and classified into 10 classes according to the rate of occurrence of bubbles, in which 0 indicates that the rate of occurrence of bubbles is 0%, 10 indicates that the rate of the Appearance of bubbles is 100%, 1 indicates that the rate of occurrence of bubbles is 0-10%, etc.

Test of excess glue (bleeding)

After performing the pressure-removing operation under pressure, the film (20 x 20 cm) was observed using an optical microscope to evaluate the problem of bleeding at the edges of openings or at the edges of the film. When the glue flows over the edge of the opening at a distance of 0.5 mm, a "bleeding problem" occurs.

The test results of the examples were shown in Tables 1 to 6.

Table 1 shows the test results of surface tackiness and lamination with respect to dry films having different solvent contents. According to the results shown in Table 1, the dry film can provide a gas dissolving effect when the solvent contained therein reaches a certain amount or more, which is beyond the expectation of the prior art. However, if the amount of solvent is too low (4.9% by weight), it can not effectively remove bubbles; if the amount of solvent is too high (64.9% by weight), surface tackiness occurs.

Tables 2-6 relate to dry films obtained by adding another solvent having a better gas dissolving effect to the resin composition.

Table 2 shows the test results of surface tackiness and lamination with respect to dry films in which the total amount of the solvent after drying is different; the total amount of solvent in the dried dry films is 4.9 wt.%, 10.4 wt.%, 15 wt.%, 18.9 wt.%, 31.6 wt.%, 40.1 Wt .-%, 52 wt .-%, and 56.4 wt .-%. In Examples 1-11 to 1-17, the second solvent is held in the dry film substantially in an amount between about 7% to 8% by weight. As shown in Table 2, the total amount of the solvent in Example 1-10 is 4.9 wt%, the bubble-dissolving effect is not good. The dry films of Examples 1-14 and 1-16 have a better bubble-dissolving effect; however, the dry film of Example 1-16 does not have the same anti-sticking effect as the dry films in other examples because the total amount of the solvent is up to 52% by weight, and the dry film of Example 1-17 has a poorer anti-sticking effect Total amount of solvent up to 66.4 wt .-% is. In addition, it can be shown by comparison between Table 1 (without second solvent) and Table 2 that with the same total amount of solvent, the dry films containing a second solvent have a lower residual rate of bubbles so that they have a better bubble dissolving effect. For example, in the dry films of Examples 1-5 and 1-13, the total amount of solvent is about 20% by weight; however, the residual rate of bubbles was rated Class 8 for Example 1-5, in which no second solvent was added, while the residual rate of bubbles for Example 1-13, in which a second solvent was added, was reduced to Grade 6. The result shows that the addition of a second solvent enhances the bubble-dissolving effect. Results of the comparison for related examples are shown in Table 7 below. Table 7 Total amount of solvent in the dried dry film (% by weight) Amount of second solvent in the dried dry film (wt%) surface tackiness Lamination test (class: residual rate of bubbles) Example 1-4 15.1 - 0 8th Example 1-12 15 7.1 0 6 Example 1-5 20.7 - 0 8th Example 1-13 18.9 7.2 0 6 Example 1-6 30.5 - 0 7 Example 1-14 31.6 7.5 0 5 Example 1-7 39.7 - 0 7 Example 1-15 40.1 7.6 1 5 Example 1-8 49.5 - 5 7 Example 1-16 52 7.7 5 4

Examples 1-19 to 1-26 in Table 3 show the test results of surface tackiness and lamination with respect to dry films having different ratios of the first solvent amount to the second solvent amount after drying while the total amount of solvent therein is the same (about 40 wt. -%). As shown in Table 3, with the same total amount of solvent, the increase of the second amount of solvent is favorable for reducing the residual rate of bubbles. In Example 1-18 of Table 3, the amount of the second solvent is larger than 3% by weight, but the total amount of the solvent is 4.9% by weight, so that the bubble-dissolving effect is not good. In Example 1-19 of Table 3, it can be seen that with the same total amount of solvent (approximately 40% by weight) the effect of Reduction of the residual rate of bubbles is not achieved when the amount of the second solvent after drying is less than 3 wt .-% (compared to Example 1-15 of Table 2). When the amount of the second solvent after drying is between 3% by weight and 45% by weight (ie, Examples 1-20 to 1-26), the residual rate of bubbles suddenly becomes Class 4, 3, 2, or even 1 decreases, indicating that the bubble-dissolving effect can be effectively improved if the amount of the second solvent after drying is between 3% by weight and 45% by weight. In addition, considering Example 1-27 of Table 3 (the total amount of solvent is approximately 50% by weight), it can be seen that when the amount of the second solvent after drying exceeds 45% by weight, an excess of glue ( Bleeding) occurs and the Antiklebwirkung is not good.

Table 4 shows the test results of surface tackiness and lamination with respect to the dry films made of different polyimide precursors or soluble polyimides with or without the addition of the second solvent. In each example, the second solvent was added to the composition in an amount of 4% by weight prior to coating and maintained between 6% and 9% by weight after drying. A comprehensive review of the results of the examples shows that all dry films made from different polyimide precursors or soluble polyimides have a gas dissolving effect and that the addition of the second solvent can further reduce the residual rate of bubbles in the dry film and thus a better effect can be obtained.

Table 5 shows the test results of surface tackiness and lamination with respect to the dry films containing different second solvents. A comprehensive overview of the examples in Table 5 shows that all solvent-containing dry films of the present invention provide a gas-dissolving effect and that selecting a suitable second solvent can further enhance the gas-dissolving effect. From the results of Examples 17-3 to 17-11 and Examples 17-12 to 17-14, it can be seen that a second solvent belonging to ethers or alcohols has a higher residual rate of bubbles, indicating that second solvents belonging to ethers or alcohols have a less significant gas-solubilizing effect than the other second solvents such as substituted or unsubstituted alkanes or esters. Among the second solvents, which are isomeric compounds, the second branched chain solvent (Example 17-3) has a better gas dissolving effect than the second straight chain solvent (Example 17-4).

Table 6 refers to the dry films which have been subjected to a blister-dissolving pressured operation after lamination. The results show that the solvent-containing dry film of the present invention can significantly reduce the residual rate of bubbles during the blast-dissolving operation under pressure and obtain excellent effects. Example 1-31 of Table 6 differs from Example 1-14 of Table 2 only by the step of the bubble-dissolving operation under pressure. The results show that Example 1-31, which employs the step of dissolving the bubbles under pressure, can reduce the residual rate of bubbles to class 0. In addition, Table 6 also shows that, in the case where the solvent is present in the dry film in a total amount of more than 60% by weight after drying (Examples 1-33 and 1-34), even if the dry film is one Bubble-dissolving operation was subjected to pressure, the improvement of the residual rate of bubbles is limited or the Antiklebwirkung is not good, although the residual rate of bubbles is improved.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• TW 095138481 [0033]
• TW 095141664 [0033]
• TW 096128743 [0033]
• TW 97151913 [0033]
• TW 100149594 [0033, 0036]
• TW 097101740 [0051]
• TW 099105794 [0051, 0057]

Claims (16)

A solvent-borne dry film comprising a support and a resin layer, wherein the resin layer comprises a resin and a solvent and the solvent is present in a total amount of at least 5% by weight based on the total weight of the resin layer. A dry film according to claim 1, wherein the solvent is present in a total amount of from 15% to 60% by weight, based on the total weight of the resin layer. A dry film according to claim 1, wherein the solvent comprises a solvent having a gas-dissolving action. A dry film according to claim 3, wherein the solvent having a gas dissolving action is present in an amount of from 5% to 60% by weight based on the total weight of the resin layer. The dry film according to claim 1, wherein the resin layer comprises: (a) a polyimide resin; and (b) a solvent, wherein the polyimide resin is a polyimide precursor or a soluble polyimide or a combination thereof. A dry film according to claim 5 wherein the solvent is selected from a first solvent, a second solvent and a combination thereof. A dry film according to claim 5, wherein the solvent is present in a total amount of from 15% to 60% by weight, based on the total weight of the resin layer. A dry film according to claim 6, wherein the first solvent is selected from dimethyl sulfoxide, diethyl sulfoxide, N, N-dimethyl-methanamide, N, N-diethylmethanamide, N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, phenol, o-cresol, m-cresol, p-cresol, xylenol, halogenated phenol, catechol, tetrahydrofuran, dioxane, dioxolane, propylene glycol monomethyl ether, tetraethylene glycol dimethyl ether, methanol, ethanol, butanol, 2-butoxyethanol, γ Butyrolactone, xylene, toluene, hexamethylphosphoramide, propylene glycol monomethyl ether acetate and a mixture thereof. A dry film according to claim 6, wherein the second solvent is selected from

a perfluoroaromatic compound, a C ₂ -C ₂₀ perfluoroalkane, tri (C ₁ -C ₆ perfluoroalkyl) amine, a perfluoroether, a C ₆ -C ₁₆ alkane, and a combination thereof, wherein: R ₁ ", R ₉ "and R ₁₀ " are each independently H, C ₁ -C ₂₀ alkyl, C ₂ -C ₂₀ alkenyl or C ₂ -C ₂₀ alkynyl; R ₇ '' is H or C ₁ -C ₃ alkyl; R ₂ "is C ₁ -C ₁₀ alkyl; R ₃ "is C ₂ -C ₂₀ alkyl or C ₁ -C ₁₀ alkyl-OC ₁ -C ₁₀ alkyl; R ₄ "and R ₅ " are each independently C ₁ -C ₁₀ alkyl or R ₄ "and R ₅ " together with the oxygen atoms to which they are attached form a 5-6 membered heterocycle; R ₆ "is C ₁ -C ₁₅ alkyl or C ₄ -C ₈ cycloalkyl; R ₈ "is C ₂ -C ₂₀ alkyl; and R ₁₁ "and R ₁₂ " are each independently C ₁ -C ₁₀ alkyl. A dry film according to claim 6, wherein the second solvent is a solvent containing fluorine, an alkyl group or an ester group. The dry film of claim 10, wherein the second solvent is selected from

A dry film according to claim 6, wherein the first solvent is present in an amount of from 0.5% to 50% by weight, based on the total weight of the resin layer. A dry film according to claim 6, wherein the second solvent is present in an amount of from 3% to 45% by weight, based on the total weight of the resin layer. A method of applying a dry film to a substrate, comprising: Laminating the dry film of claim 1 on the substrate in a manner that the resin layer of the dry film faces the substrate. The method of claim 14, wherein the substrate is a printed circuit board, a wafer, a display or a touch panel. The method of claim 14, further comprising performing a pressure-dissolving blister-dissolving operation after laminating the dry film on a substrate in a manner that the resin layer of the dry film faces the substrate.

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